This specification relates to presentations systems.
Conventional presentation systems typically display output from a presentation application. A presentation application includes any application capable of producing visual output, including, for example, slide presentation applications, word processing applications, and web browsers. Typically, the output is displayed to a group of individual users, for example, during a lecture, meeting, class, or other presentation. Users can include a presenting user managing the presentation as well as participating users. The output from the presentation application can be displayed, for example, on a projected screen or a collection of individual display devices (e.g., computer monitors).
The display output of the presentation application can be redirected from a local display to a display on a non-local device. This redirection is typically referred to as teleporting. For example, a mobile user can export the display output of running applications to other devices as the mobile user changes location. The presentation application does not need to be re-opened or transmitted during teleporting. Teleporting can be applied to the entire display output of the device or to the display output of one or more application specific displays (e.g., application windows).
The display output of the presentation application can also be shared among several users using different devices. This is typically referred to as display multiplexing. Similar to teleporting, the shared display output can be an entire display of a particular device or just one or more particular application windows. Display multiplexing can be used, for example, in electronic learning or helpdesk applications.
Teleportation and display multiplexing typically use virtual frame buffers. A virtual frame buffer (VFB) is an application that mimics a graphics card with respect to both graphics memory and interface to a presentation application. The display output of the presentation application can be routed to the VFB instead of a graphics card memory (i.e., a real frame buffer). The size of the frame buffer corresponds to the display resolution, e.g., 1024 pixels per line×768 pixels per row×3 bytes per pixel. The content of a frame buffer of one device can be sent to a remote virtual frame buffer (rVFB) on a remote device in order to provide the display output to other devices in teleportation and display multiplexing.